Why are there 3 wires to my wireless camera

Thread Starter

pacothegreat

Joined Jan 10, 2012
4
Hi Guys,

Not a sparky myself. I just bought one of these mini wireless cameras
http://www.buy.com/prod/2-4ghz-wireless-surveillance-camera-kit-w-1-channel-wireless-receiver/q/sellerid/28663446/loc/111/210663752.html
I noticed that the power jack was pretty heavy and I want to use it on an RC helicopter. Without thinking much, I cut the jack off and noticed that there was three wires coming out of the camera. Now I realize it is some sort of special jack. Not sure what it does. I want to wire it to a 9 volt battery (an adapter for this came with the camera) Can you tell me what the special jack does? Do I need the third wire?

Thanks!
 

thatoneguy

Joined Feb 19, 2009
6,359
Is audio over the wireless as well?

Does the jack have 3 wires, or is it a 2 wire barrel jack, with 3 wires running to it?

I'd suggest against using a 9V PP3 (rectangular battery), use 6 AA's in a holder with a 9V snap out of it. Reason is 9V are rated anywhere from 200mAH-350mAH, while a AA battery is rated for 2,000 mAH or more (10x the life).
 

Thread Starter

pacothegreat

Joined Jan 10, 2012
4
It's a wireless camera...so shouldn't the video be sent from the antenna? It looks like a normal mini-jack, except a little bigger on the outside. I did a continuity check from the center pin and it's open from there to all the wires leading out. Before I tore it apart, it worked fine with a two lead 9-volt battery plugged into it. I think the jack must serve some sort of extra function, like power conversion. That's the mystery. I would cut it open to see what's inside, but that would probably sacrifice the camera. Instead, I think I will solder it back on.
 

thatoneguy

Joined Feb 19, 2009
6,359
It's a wireless camera...so shouldn't the video be sent from the antenna? It looks like a normal mini-jack, except a little bigger on the outside. I did a continuity check from the center pin and it's open from there to all the wires leading out. Before I tore it apart, it worked fine with a two lead 9-volt battery plugged into it. I think the jack must serve some sort of extra function, like power conversion. That's the mystery. I would cut it open to see what's inside, but that would probably sacrifice the camera. Instead, I think I will solder it back on.
If it still works, just use a 9V adapter to power it, or batteries. Though we are curious what the 3rd wire does, if it isn't broken, no bother in ripping it apart.
 

Georacer

Joined Nov 25, 2009
5,182
Stop trolling him Rifaa.

However, if you definitely don't need the power plug, why don't you cut it open and check the connections. I for one, am curious.

You can do it if you clamp down the plug and slit it with a utility knife across the seam.

Be extra careful not to cut your fingers!!!
 

R!f@@

Joined Apr 2, 2009
9,734
Trolling ? :confused:

I am trying to find what the darn 3rd wire does.

He cut it, why can't he rip it up.
OK...can you open the adapter?
 

debe

Joined Sep 21, 2010
1,179
The White wire is Video. The Red wire is Positive power. Black wire is Negative power. Standard wiring colours for these cameras. I usem for rev cameras on vehicles. If hes gone use it in a RC Helicopter then batery weight is every thing.
 

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Georacer

Joined Nov 25, 2009
5,182
As he said, he cut it because the adapter was too bulky for his build.

@ debe
The question arises from the fact that the adapter has only two pins, the video is wireless. Am I right pacothegreat?
 

Thread Starter

pacothegreat

Joined Jan 10, 2012
4
so...I am still using the camera so I don't want to destroy my jack. However, my former NASA EE coworker thinks its a switching power supply. When I get some spare time we are going to do some experiments on it (non destructive). I'll post then.
 

thatoneguy

Joined Feb 19, 2009
6,359
Some of those little switchers have a sense line for feedback to the controller used for load regulation.
But the barrel connector only seems to have two connections, inside and outside, from what he has posted.

I'm wondering if there isn't an "upgrade/downgrade" for this camera to be wired, in which case they pull out the power only jack, and put in a 3 wire jack to send the video back over the white wire.

It is a lot more economical to make one PCB and chassis then remove lots of parts for a lower priced model, such as wireless, on screen timestamp, etc..
 

radiohead

Joined May 28, 2009
508
Connect your power to the black and red wires and see if you have video feed. If not, then the white wire is necessary for some function..like a microphone. Look for a tiny hole on the camera housing somewhere where the mic would be.
 
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